The Service Availability Forum (SA Forum or SAF) is a consortium of industry-leading companies promoting a set of open specifications that enables the creation and deployment of highly available and mission critical services. As a standardization body, the SA Forum has defined a set of open specifications, including the Software Management Framework (SMF), for middleware services. The SMF is defined to support the upgrade of software and hardware entities in a SA Forum compliant system.
An SA Forum compliant system can be characterized by its deployment configuration. The deployment configuration may need to be changed at any time, for example, to tune its performance by creating new instances of an entity type, by modifying parts of the configuration, or by removing some of the existing instances. In some cases, it is necessary to downgrade entities to an earlier version of their base entity type.
The SMF orchestrates the migration of a live system from one deployment configuration to another while ensuring service availability. In SMF terms, this migration process is called an upgrade campaign. The SMF defines an XML schema to specify an upgrade campaign. The upgrade campaign is a script of actions and configuration changes that lead to the target configuration.
The SMF describes various upgrade methods; however, these methods cannot handle dependencies between the software entities without outage, e.g., if un-installation of the old software require the old operating system, while installation of the new software requires the new operating system. Further, the existing upgrade methods cannot be used “as-is” for all kinds of different system topologies without causing a negative impact on service availability.